“Doctors want to ban smoking in cars… even if you’re on your own,” the Daily Mail has reported. The Mail and most other newspapers and news broadcasters covered the call from the British Medical Association (BMA) for a government ban on drivers and passengers smoking in private vehicles.

In a briefing paper from its board of science, the BMA argues that there is strong evidence that smoking in cars exposes non-smokers to high levels of secondhand smoke (SHS), with about 23 times more toxins than in a smoky bar. A blanket ban on smoking in cars, it argues, would protect vulnerable groups such as children and the elderly, who often have no choice about taking a journey in a smoky vehicle. The BMA’s report also highlighted the risk of injury and death from road traffic accidents as a result of the distraction of smoking while driving. However, the report provided only a small amount of evidence on this issue.

The briefing paper coincided with the second reading of a private members' bill calling for a ban on smoking in private vehicles when children are present. The bill is due to be debated on November 25.

Why is this in the news today?

The BMA has produced a briefing paper on smoking in cars, in response to a motion debated at its annual representative meeting earlier this year, where its members voted in favour of extending smokefree legislation to cover private motor vehicles. The association has issued a press release highlighting its reasons for supporting such a move, and urging a ‘bold and courageous step of banning smoking in private vehicles’ by UK governments.

Why is secondhand smoke dangerous?

In the paper the BMA points out that exposure to secondhand smoke (SHS) is a major public health concern. In the UK, an estimated 23 children and 4,000 adults die each year due to SHS. Tobacco smoke contains 4,000 known chemicals, 69 of which are known or probable carcinogens, it says. SHS, which consists of both ‘mainstream’ smoke exhaled by the smoker and ‘sidestream’ smoke from the burning of tobacco products, contains several major classes of known carcinogens as well as toxins and irritants.

There is particularly compelling evidence about the adverse effects of SHS on children, who absorb more pollutants, says the BMA. It reports that children are more susceptible to the harmful effects of SHS because they breathe more rapidly, absorb more pollutants because of their size, have less developed immune systems and are more vulnerable to cellular mutations.

A child’s immune system is also less developed than that of an adult, and lacks the necessary defences to deal with the harms of SHS. Evidence suggests that SHS increases the risk of sudden infant death syndrome (cot death), children’s respiratory tract infections, ear diseases, and other conditions associated with impairment of lung function, such as asthma.

What does smokefree legislation cover at present?

The current smokefree legislation was introduced in England in July 2007. It requires all enclosed premises where people work or where the public have access, to be smokefree. This includes public transport and taxis. Current regulations say enclosed vehicles should be smokefree at all times if they are used by the public or if they are used in the course of paid or voluntary work by more than one person. At present, UK smokefree legislation does not apply to private vehicles.

Why does the BMA want the legislation extended to cover private vehicles?

The BMA says that research has confirmed that smoking in vehicles in particular, exposes non-smokers to high levels of SHS, due to the restrictive internal environment. There is evidence to suggest that the levels of SHS present in vehicles can be a serious health hazard to both adults and children. In addition, studies have demonstrated that the concentration of toxins in a smoke-filled vehicle is 23 times greater than that of a smoky bar.

There is evidence to suggest that private vehicles are a significant source of SHS exposure for children as well as adults. In England, an estimated 30% of smokers smoke in their vehicles and more than half of all journeys made by children under 16 are by private vehicle. One study has found that more than half of 8-15 year olds have been exposed to cigarette smoke in a vehicle.

Why does the BMA not just call to ban smoking in cars when children are present?

The BMA argues that banning smoking in all private vehicles would be the simplest and most easily enforceable measure.

They also point out that SHS in vehicles is a serious health hazard for adults, particularly elderly people who are prone to respiratory problems. One report found that 26% of adult non-smokers are exposed to SHS in vehicles. Residual toxins are known to remain in the interior furnishings of cars long after a cigarette has burnt out. This means that simply not smoking when driving with passengers does not prevent the harmful effects of SHS. A total ban on tobacco, regardless of who is present, would keep vehicles free from residual smoke toxins, the BMA claims.

The BMA report also says there is evidence to suggest that the physical act of smoking itself could be a risk to road safety. It bases this claim on four studies that looked different aspects of vehicle crashes and smoking habits. The report also points out that the UK Highway Code lists smoking as a distraction from safe driving, and that drivers can be fined if they are found to drive recklessly because they have been smoking.

What does the BMA say about freedom of choice?

Several news reports included the views of the pro-smoking organisation Forest, which claimed that there was ‘no justification’ for a ban on smoking in cars. In its report, the BMA argues that smokefree legislation already restricts people’s freedom to smoke, for the benefit of those around them. While most adults have the freedom to leave a smoky vehicle or ask a smoker to stop smoking, children and other vulnerable groups such as the elderly and disabled are often dependent on their parents or carers and are not free to make the same choices.

What is the government’s position?

In the latest tobacco control plan, published in March 2011, the Department of Health said it favoured a policy aimed at increasing public awareness of the risks of SHS. It said this would lead to greater personal responsibility to keep homes and vehicles free of smoke. And in response to the BMA’s paper, a spokesperson for the Department of Health is quoted in The Daily Telegraph as saying: ‘We do not believe that legislation is the most effective way to encourage people to change their behaviour’.

A national marketing campaign is reportedly due to be launched next year to remind smokers of the risks of exposing children and adults to secondhand smoke.

In June 2011, a private members’ bill was presented to the House of Commons to ban smoking in private vehicles when children are present. It won a slight majority in favour and is due to be debated on November 25. In Wales, the government is considering a ban on smoking in vehicles when children are present.

What does the report say about public opinion?

The BMA says that smokefree legislation banning smoking in public places has been supported by 80% of the English population (2002 data from the Office for National Statistics), and 90% of non-smokers (a 2010 report by the Royal College of Physicians). The association says that public support for a ban on smoking in private cars has increased in recent years, as demonstrated by opinion polls. These include two YouGov polls that found majority support among adults in England for a ban on smoking in vehicles (2009), and 74% of adults in England supported a ban on smoking in vehicles with children (August 2010).

The BMA also highlights a British Lung Foundation study that showed that 86% of UK children surveyed want to stop people smoking when they were present in the vehicle.